To further investigate the mechanisms underlying the MGMT loss in HP-associated GC, we successfully constructed stable transfectant: CagA-expressing SGC-7901 cell line (CagA+ SGC-7901), pcDNA3.1 empty vector transfected SGC-7901 (EV-SGC-7901) cell line serves as control. The gene discussed is MGMT; the disease is gastric cancer.